function s1_hello() {
     echo "hello, world!"
}

function s2_tell_who_i_am() {
     whoami
}

function s3_which_distro_do_i_use() {
     if [ -f /etc/os-release ]; then
	 source /etc/os-release
	 echo "$NAME=\"$NAME\""
     else
	 echo "无法确定发行版"
     fi
}

function s4_view_my_cpu_arch() {
     uname -m
}

function s5_show_first_scsi_disk_size() {
        local dsik_size_bytes=$(lsblk -b | \grep -E '^sda' |awk '{print $4')
	if [ -n "$disk_size_bytes" ]; then
		local disk_size_gb=$(echo "scale=0; $disk_size_bytes / 1000000000" | bc)
		echo "$disk_size_gb"
	else
		echo "未找到第一块 SCSI 硬盘"
	fi
}

function s6_show_main_memory_size_in_megabytes() {
     free -m | grep "Mem:" | awk '{print $2}'
}

